Refreshing a 502
 

Hello all,
So I am in the process of "Freshening/ rebuilding" my 502 and now that it's torn down I have a few questions, the heads are GM (#14097088) that are ported and polished, running an ISKY Race cam.

Style: Hydraulic roller tappet
Basic Operating RPM Range: 3,000-7,000
Intake Duration at 050 inch Lift: 238
Exhaust Duration at 050 inch Lift: 248
Duration at 050 inch Lift: 238 int./248 exh.
Advertised Intake Duration: 284
Advertised Exhaust Duration: 294
Advertised Duration: 284 int./294 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.578 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.608 in.
Valve Lift with Factory Rocker Arm Ratio: 0.578 int./0.608 exh.
Lobe Separation (degrees): 110
Computer-Controlled Compatible: No

With the basics above would changing to aluminum heads be a benefit? Any other recommendations?

I am going to Morel Lifters with Scorpion 1.7 Marine Endurance Roller Rockers

Thanks

2 things from me:

The words ported and polished mean nothing to me. Who did the port work and do they know what the helll they are doing ?

What exhaust are you running and are they dry ?

Ooops: a third thing - what compression are we aiming for ?

No idea who did the port/ polish and right now I'm running wet exhaust but will be changing to dry either with headers or fab the Gil's I have. The boat ran great this summer with what I have, just looking to make sure I don't have any or introduce any problems

Well after debating (Not really) and talking with Bob (Marine Kinetics) decided to go with a custom cam, AFR Aluminum heads, Holley EFI, Morel Lifters, Scorpion 1.7 Endurance Rockers, DUI Distributor and Moton Rods.... I'm still out on whether replacing the pistons or going to CP Carrillo bullet.

1st thing is getting the block in for hot tanking and cylinder wall check and Crank in for magna flux.... Will keep posting on the build

Forgot to add Borgie's help.. Thank you

Looks like you to are getting info from one of the best here. With your build what is the HP and TQ numbers Bob is coming up with?

I'm betting the 650 range.

I Gonna be a sweet motor man! Bob is a true gentleman and his knowledge on what works is truly amazing! Take this and add some of Alex Haxbys , (holley efi) and you have a perfect recipe. I'm looking forward to your results!

What size AFR heads are you going to run? Cometic MLS gaskets? Head studs? Make sure you have the proper RA finish on your block with the MLS gaskets - heads should come with proper finish already. You have mostly blind head bold holes in the 502 block, so shouldn't be any major concerns with sealing the threads. Follow Bob's advice and run a good, stout set of pushrods too. You're gonna be a happy boy.

Good job ditching the GM 088 iron heads. They suck.

do you boat in fresh or salt water?

We will be right around the 650+ mark but more about reliability..... "If" I can get 700 i will spend the extra coin, but truthfully it's reliability

Looking at 315 AFR but that may change depending on what comes back with the cylinder and crank check. Will most definitely be Cometic Gaskets, ARP Studs and Manton pushrods.... And yes even with only the couple of calls I have made to Bob it's going to be exactly what I am after

Borgie has been a HUGE help to, very knowledgeable and helpful.. Thanks again

If your interested I have a set of 088 heads that are in great shape for sale....LOL

Strictly fresh water, I don't have a closed system and after spending all this money want it to last as long as it can

So maybe someone can give me some insight, my block is as follows "14096859 Big Block V8 502, 4 bolt, Generation V, HO" From what I have read this is a marine block with thin main bulkheads.
Is there a difference between a standard 502 Gen V? What is "Thin Main bulkheads"?

Thanks

After a lengthy and well-informed discussion with Bob today we decided to make the 502 a 509 with a bore of 4.500.

I'm sure your going to love the way it turns out

As pleased as I was with my engine I still had some issues that needed attention and whoever built the built the engine before used some street parts which after time is an automatic failure, with the EFI and Bobs recipe it's nothing but great times ahead :D

Looking for someone to weld an O2 bung in the riser/s, I have GIL dry to tip exhaust risers. PM me if this is something you can do

Thanks
Bryan

Make sure you do the necessary upgrades on the marine side. Big oil cooler/lines no npt 90's ect ect. I would put a decent oil pan on it to. More power more rpms means more heat.
Then after the motor is squared away probably gonna want hydraulic steering bigger trim tabs and the list goes on. Oh! And if your boat doesn't have motor plates in it you really should add them 650+hp will rip the stock mounts right out of that thing...

So last week and this week I have been on the phone with Bob and getting a serious education, as many here have said and I will reiterate Mr. Madera is 2nd to none with knowledge and sharing his education, a true gentleman, scholar and one of the nicest people I have met/ talked with.

Next week I will be ordering the pistons and connecting rods (JE Piston 4.500"x4.00"_6.135" + 7cc Dome and Connecting Rods, Forged 4340 Steel, H-Beam, 6.135 in. Length) so the machine shop can get started.

Just curious not trying to throw a monkey wrench in your program but why a stock length rod?

Because the difference in angle between stock 6.135 and 6.385 is minimal with 9:7-1 compression.... Would have had to get custom pistons made

So the Holley EFI showed up today thanks to a good friend... Thankshttp://i129.photobucket.com/albums/p...ps21ec8c73.jpg

No way ! They still make those ? I think it was the commander 950 , I have one system left with a Cutler branded dart size high rise intake .billet throttle body with adjustable linkage the orig accell control unit gave up the ghost way back in the day ,have modern ecm and injectors now .great looking unit ,say goodbye to any of the 502 mpi vapor lock issues too ,if you had any